1 2 /*- 3 * SPDX-License-Identifier: ISC 4 * 5 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 6 * Copyright (c) 1996-1999 by Internet Software Consortium. 7 * 8 * Permission to use, copy, modify, and distribute this software for any 9 * purpose with or without fee is hereby granted, provided that the above 10 * copyright notice and this permission notice appear in all copies. 11 * 12 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 18 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 19 */ 20 21 /*! \file 22 * \brief 23 * Based on the Dynamic DNS reference implementation by Viraj Bais 24 * <viraj_bais@ccm.fm.intel.com> 25 */ 26 27 #include "port_before.h" 28 29 #include <sys/param.h> 30 #include <sys/socket.h> 31 #include <sys/time.h> 32 33 #include <netinet/in.h> 34 #include <arpa/inet.h> 35 #include <arpa/nameser.h> 36 37 #include <errno.h> 38 #include <limits.h> 39 #include <netdb.h> 40 #include <res_update.h> 41 #include <stdarg.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 46 #include <isc/list.h> 47 #include <resolv.h> 48 49 #include "port_after.h" 50 #include "res_private.h" 51 52 /*% 53 * Separate a linked list of records into groups so that all records 54 * in a group will belong to a single zone on the nameserver. 55 * Create a dynamic update packet for each zone and send it to the 56 * nameservers for that zone, and await answer. 57 * Abort if error occurs in updating any zone. 58 * Return the number of zones updated on success, < 0 on error. 59 * 60 * On error, caller must deal with the unsynchronized zones 61 * eg. an A record might have been successfully added to the forward 62 * zone but the corresponding PTR record would be missing if error 63 * was encountered while updating the reverse zone. 64 */ 65 66 struct zonegrp { 67 char z_origin[MAXDNAME]; 68 ns_class z_class; 69 union res_sockaddr_union z_nsaddrs[MAXNS]; 70 int z_nscount; 71 int z_flags; 72 LIST(ns_updrec) z_rrlist; 73 LINK(struct zonegrp) z_link; 74 }; 75 76 #define ZG_F_ZONESECTADDED 0x0001 77 78 /* Forward. */ 79 80 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2); 81 82 /* Macros. */ 83 84 #define DPRINTF(x) do {\ 85 int save_errno = errno; \ 86 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \ 87 errno = save_errno; \ 88 } while (0) 89 90 /* Public. */ 91 92 int 93 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) { 94 ns_updrec *rrecp; 95 u_char answer[PACKETSZ]; 96 u_char *packet; 97 struct zonegrp *zptr, tgrp; 98 LIST(struct zonegrp) zgrps; 99 int nzones = 0, nscount = 0, n; 100 union res_sockaddr_union nsaddrs[MAXNS]; 101 102 packet = malloc(NS_MAXMSG); 103 if (packet == NULL) { 104 DPRINTF(("malloc failed")); 105 return (0); 106 } 107 /* Thread all of the updates onto a list of groups. */ 108 INIT_LIST(zgrps); 109 memset(&tgrp, 0, sizeof (tgrp)); 110 for (rrecp = rrecp_in; rrecp; 111 rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) { 112 int nscnt; 113 /* Find the origin for it if there is one. */ 114 tgrp.z_class = rrecp->r_class; 115 nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class, 116 RES_EXHAUSTIVE, tgrp.z_origin, 117 sizeof tgrp.z_origin, 118 tgrp.z_nsaddrs, MAXNS); 119 if (nscnt <= 0) { 120 DPRINTF(("res_findzonecut failed (%d)", nscnt)); 121 goto done; 122 } 123 tgrp.z_nscount = nscnt; 124 /* Find the group for it if there is one. */ 125 for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) 126 if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 && 127 tgrp.z_class == zptr->z_class) 128 break; 129 /* Make a group for it if there isn't one. */ 130 if (zptr == NULL) { 131 zptr = malloc(sizeof *zptr); 132 if (zptr == NULL) { 133 DPRINTF(("malloc failed")); 134 goto done; 135 } 136 *zptr = tgrp; 137 zptr->z_flags = 0; 138 INIT_LINK(zptr, z_link); 139 INIT_LIST(zptr->z_rrlist); 140 APPEND(zgrps, zptr, z_link); 141 } 142 /* Thread this rrecp onto the right group. */ 143 APPEND(zptr->z_rrlist, rrecp, r_glink); 144 } 145 146 for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) { 147 /* Construct zone section and prepend it. */ 148 rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin, 149 zptr->z_class, ns_t_soa, 0); 150 if (rrecp == NULL) { 151 DPRINTF(("res_mkupdrec failed")); 152 goto done; 153 } 154 PREPEND(zptr->z_rrlist, rrecp, r_glink); 155 zptr->z_flags |= ZG_F_ZONESECTADDED; 156 157 /* Marshall the update message. */ 158 n = res_nmkupdate(statp, HEAD(zptr->z_rrlist), 159 packet, NS_MAXMSG); 160 DPRINTF(("res_mkupdate -> %d", n)); 161 if (n < 0) 162 goto done; 163 164 /* Temporarily replace the resolver's nameserver set. */ 165 nscount = res_getservers(statp, nsaddrs, MAXNS); 166 res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount); 167 168 /* Send the update and remember the result. */ 169 if (key != NULL) { 170 #ifdef _LIBC 171 DPRINTF(("TSIG is not supported\n")); 172 RES_SET_H_ERRNO(statp, NO_RECOVERY); 173 goto done; 174 #else 175 n = res_nsendsigned(statp, packet, n, key, 176 answer, sizeof answer); 177 #endif 178 } else 179 n = res_nsend(statp, packet, n, answer, sizeof answer); 180 if (n < 0) { 181 DPRINTF(("res_nsend: send error, n=%d (%s)\n", 182 n, strerror(errno))); 183 goto done; 184 } 185 if (((HEADER *)answer)->rcode == NOERROR) 186 nzones++; 187 188 /* Restore resolver's nameserver set. */ 189 res_setservers(statp, nsaddrs, nscount); 190 nscount = 0; 191 } 192 done: 193 while (!EMPTY(zgrps)) { 194 zptr = HEAD(zgrps); 195 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0) 196 res_freeupdrec(HEAD(zptr->z_rrlist)); 197 UNLINK(zgrps, zptr, z_link); 198 free(zptr); 199 } 200 if (nscount != 0) 201 res_setservers(statp, nsaddrs, nscount); 202 203 free(packet); 204 return (nzones); 205 } 206 207 /* Private. */ 208 209 static void 210 res_dprintf(const char *fmt, ...) { 211 va_list ap; 212 213 va_start(ap, fmt); 214 fputs(";; res_nupdate: ", stderr); 215 vfprintf(stderr, fmt, ap); 216 fputc('\n', stderr); 217 va_end(ap); 218 } 219